The overall objective of this contract is to produce a SEER-Medicare resource (SEER-Medicare Light) to facilitate analyses of SEER-Medicare data by researchers. The approach will be incremental and as proof of concept this contract will produce files for breast cancer cases containing information on care utilization that includes use of systemic therapy, cancer related surgery, radiation therapy, hospitalizations, and costs. The aim is to reorganize the SEER-Medicare files by type of services (e.g. systemic therapy, surgery etc.) and not by billing provider as it is organized now. This contract will produce the files and documentation for female breast cancer.